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Old 05-18-2011, 07:32 AM
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wint wint is offline
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Default How to: OBS Downpipe install

This write up is for installing a Diamond Eye Performance downpipe on a 1994.5-1997 PSD OBS truck

Installing a downpipe in a obs is fairly simple as long as your careful and patient. you'll need some simple tools to complete this task: a 7/16 deep socket, a 9/16 open end wrench(a gear wrench is awesome for this if you have one, a 9/16 socket, short extensions and ratchet to fit sockets, a small pry bar, some wire snips, and a good sawzall with a good blade(the longer the blade the better.

First you'll want to disconnect your stock downpipe from your exhaust system.

Next you'll want to go up top on the turbo and take the stocker off from the turbo. Spray the nut with WD-40 or another penetrating lube to help along you'll need a 7/16 deep socket with a extension (to make it easier on you) and take the clamp loose on the exhaust side of the turbo.

(picture is with new DP installed)

After taking the nut completely off the bolt take your pry bar and lightly pry up on the bottom of the clamp. There are 3 sections to the clamp and each have to be popped off. be careful not to break the clamp.

Once you have the DP loose from the turbo you can start cutting. Make your first cut under the truck. You'll have to first remove the heat shield around the stock DP with the wire snips just cut the bands. Its not 100% necessary but it wont bind up you blade. Make the cut before the transmission cross members. I highly recommend eye protection. (been there done that)
Make your second cut up top on the "cobra head" of the DP. After you make your second cut the middle section of the DP will come right out.

Picture of the "cobra head" cut.

You'll end up with 3 pieces that look like this.

Now its time for putting in the new DP.

The first thing to do is drop your turbo side piece of the new DP down the hole to see where the firewall needs to be moved. I cant say 100% where you'll have to move it but you can usually eyeball it and get it right. To move the firewall i used a hydraulic pry, I understand not all of us have that. Some have used a baseball bat, a pry bar, a hammer (if you can swing it lol) however you need to move it without damaging anything vital.

Its hard to take pics but you get the idea.

Once you have the firewall moved you can slide the turbo side piece of the new DP on. I found that it will have to go on from under the truck. Slip the clamp on and get it tight enough that it will hold the piece up but you can still adjust it. Get the first piece lined up so that it doesn't touch anything as it goes down. Once you have it lined up slide your second piece onto the first piece.
Go up top and tighten the turbo clamp down, then tighten the clamp holding the 2 pieces of the DP together. After you get everything tight and put back together you are done.

What i am going to do though since I have a automatic tranny
I'm going to wrap the new DP with the stock heat shield to keep the extra heat from the tranny. This isn't necessary but it seemed like a good safety net to me. just an idea to share.

All that is left to do is enjoy a move responsive truck (i felt) and more turbo whistle

Old 05-18-2011, 08:05 AM
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oneton oneton is offline
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great first tech post wint.maybe gare,crowz,or another mod can make it a sticky
96 f350 4wd auto cclb
97 f350 4wd auto rclb
Old 05-18-2011, 10:35 AM
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swamp_ratt swamp_ratt is offline
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Good write up dan!
1997 F350 CCLB P-24v ZF5 4x4
Old 05-21-2011, 10:33 PM
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7.3psd97444 7.3psd97444 is offline
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Great write up. Specially since this is one of the first mods to do to an OBS.
97 RCLB 7.3 5-Speed
Valair ceramic single disk clutch, Full Force 238/100's, Adrenaline HPOP, Gear Head tuning, Marty's efuel, S&B, MBRP, Isspro, Mag-Hytec
Full sound system: Kicker-Kenwood
BILLET BADGES, 20x12's and 420's, On-Board Air, Few other cosmetics
Old 05-21-2011, 10:43 PM
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Tom S Tom S is offline
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On some trucks it pretty much takes a porta power to get the clearance. Not the norm but it does happen. The cab can be all the way forward and the engine all the way back to it gets tight. I slide the motor all the way forward in the mounts to help on my truck.
Old 05-21-2011, 10:45 PM
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You can also recycle some of that pipe insulation to help keep heat off the transmission and floor pan on your new downpipe using some hose clamps.

An Easy Seal or similar band clamp works nice to clamp the pipe but make so later on you can get it apart. It does not crimp the pipe at the clamp.
Old 07-04-2011, 05:48 PM
Irishcream Irishcream is offline
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I'd suggest a buddy up top lining that DP up to the turbo while you stay under the truck guiding it past the tranny and heat shield on the firewall.
Old 07-14-2011, 02:42 PM
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Pstroke96 Pstroke96 is offline
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you can do it yourself. but its alot easier with a second person
96 F350 reg cab 4X4
260,000 miles and counting
tymar intake
5 inch straight pipe
cale's tunes
isspro ev2 gauges
rigid industries light bar and D2's

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